Monster Energy/Yamalube/Star Racing Yamaha’s Mitchell Oldenburg will be sidelined for the opening round of Lucas Oil AMA Pro Motocross this Saturday at Hangtown after suffering a third-degree burn on his buttocks at the Monster Energy AMA Supercross season finale in Las Vegas.

In the 250 LCQ in Las Vegas, Oldenburg went down in the whoops and the bike came down on top of him (as seen in the Instagram post below). According to Oldenburg, he went to a burn specialist in San Diego on Thursday after the race and doctors discovered he suffered a third-degree burn and “full thickness,” which meant the injury would not heal.

Oldenburg underwent surgery for a skin graft on Sunday morning and said he is required to remain in the hospital for a minimum of five days. At this time, a return date has not been determined.